Aftertreatment devices are well known and widely used in various internal combustion engine applications for the aftertreatment of engine exhaust gases. Such devices as diesel oxidation catalysts (DOC) and diesel particulate filters (DPF) have been useful for handling and/or removing harmful constituents, including carbon monoxide, nitric oxide, unburned hydrocarbons, and soot in the exhaust stream of an engine.
As the DPF collects particulate matter such as soot from the exhaust gas, a back pressure will increase. Unless soot is removed, the accumulation of the soot in the filter can lead to fuel inefficiencies.
In order to remove the soot in the DPF, the DPF is often times regenerated by converting the trapped soot to carbon dioxide in the presence of heat. The healthiness (i.e. the extent of soot removal) of the regeneration process is often determined based on delta pressure based soot load estimates. However, inaccuracies in determining the estimates can lead to failure modes such as uncontrolled regeneration or decreased fuel economy. Thus, there is a need to increase the accuracy of delta pressure based soot load estimates.